class_docstr: Speaker Diarization model
  
  If "attractor" is "None", SA-EEND will be used.
  Else if "attractor" is not "None", EEND-EDA will be used.
  For the details about SA-EEND and EEND-EDA, refer to the following papers:
  SA-EEND: https://arxiv.org/pdf/1909.06247.pdf
  EEND-EDA: https://arxiv.org/pdf/2005.09921.pdf, https://arxiv.org/pdf/2106.10654.pdf
code: def create_length_mask(self, length, max_len, num_output):
      batch_size = len(length)
      mask = torch.zeros(batch_size, max_len, num_output)
      for i in range(batch_size):
          mask[i, : length[i], :] = 1
      mask = to_device(self, mask)
      return mask
  
imports: from contextlib import contextmanager
  from itertools import permutations
  from typing import Dict, Optional, Tuple
  import numpy
  import torch
  import torch.nn.functional
  from packaging.version import parse
  from typeguard import check_argument_types
  from espnet2.asr.encoder.abs_encoder import AbsEncoder
  from espnet2.asr.frontend.abs_frontend import AbsFrontend
  from espnet2.asr.specaug.abs_specaug import AbsSpecAug
  from espnet2.diar.attractor.abs_attractor import AbsAttractor
  from espnet2.diar.decoder.abs_decoder import AbsDecoder
  from espnet2.layers.abs_normalize import AbsNormalize
  from espnet2.torch_utils.device_funcs import force_gatherable
  from espnet2.train.abs_espnet_model import AbsESPnetModel
  from espnet.nets.pytorch_backend.nets_utils import to_device
label_desc: Use image node_id 8 for calling the ESPnetDiarizationModel obj's underlying member method code with example usage: obj.create_length_mask(length, max_len, num_output) and returns: mask